1. Field of the Invention
The invention relates to a display apparatus. More particularly, the invention relates to a stereo display apparatus.
2. Description of Related Art
Generally, most traditional display apparatuses display plane image and lack three-dimension effect. In addition, some stereo display apparatuses provide three-dimension effect by displaying different images for right eye and left eye respectively. However, stereo image provided by this kind of stereo display apparatus is limited at a specific observing angle. For example, when this kind of stereo display apparatus displays the front of an object, the user is unable to observe the back of the object.
A conventional stereo display apparatus divides image provided by a projector into 24 sub-images arranged as a circle, and the 24 sub-images are projected onto a top reflecting mirror. The top reflecting mirror reflects the 24 sub-images respectively onto 24 reflecting mirrors arranged as a circle, and the 24 reflecting minors reflect the 24 sub-images onto a rotating screen surrounded by the 24 reflecting mirrors.
The 24 sub-images represent appearance of an object at 24 different view angles. The screen is capable of rotating to project the 24 sub-images in 24 different directions, such that a user may observe appearances of an object at these view angles by turning 360 degrees relatively to the stereo display apparatus. Thus, for eyes of a user, an object is created in the space for providing a vivid stereo display effect.
However, the image projected by the projector is divided into 24 sub-images, and the region surrounded by the 24 sub-images is not used, such that the resolution of this kind of stereo display apparatus is very low. In addition, in this kind of stereo display apparatus, the screen is disposed between the projector and the top reflector. For rotating the screen, a motor is disposed over the projector. Thus, it is hard to firmly support the screen and the motor, such that the structure is not stable and the screen is likely to be swayed.
Further, the motor is disposed on a light path of an image beam projected by the projector, such that interference by stray light may be happened. In another aspect, a projector with larger size is required for this kind of stereo display apparatus, such that the size of the stereo display apparatus is larger.
In U.S. Pat. No. 6,765,566, a screen, a projecting device, and two reflecting mirrors are disclosed in FIG. 13, wherein the screen and the two reflecting mirrors are capable of rotating along an axis. Besides, a screen, a light valve, a projecting lens, a reflecting minor, and a light source are disclosed in FIG. 17 of this US patent, wherein the screen, the light valve, the projecting lens, and the reflecting mirror are capable of rotating along an axis.
In addition, U.S. Pat. No. 6,064,423, no. 6554430, no. 7059729, no. 7168809, and no. 7520615 also provide several stereo display apparatus systems.